Method of extracting phenols and the like



Patented Oct. 10, 1933 METHOD OF EXTRACTING' PHENOLS AND THE LIKE. Ralph H. McKee, Jersey" City, N, J.

No, Drawing. Application A pril s, 1927, Serial No, 182,181. RenewedDccember 28, 1932 is Claims. 1 (01160 -154) This. invention relatesto a process of sepa= ratingcertain ingredients of oils from the other ingredients occurring therewith in such oilsyand more particularly toa process of extracting Ftar acids or phenols from. tar oil.

A principal object of this invention isto providea simple and economical process of extract ing. and isolating certain of r the substantially water insoluble ingredients from oils such as tar oils, naturally occurring petroleum :oils, shale oils, and the like by treating such oils with a solution of an organic material-capable of dissolving such ingredients when the solution is in concentrated form but incapable of dissolving to a substantial extent or retaining such ingredients in solution when the solution is in dilute or weakcondition.

A further object of this invention is to provide an eflicient process for extracting certain ingre dients such as tar acids or phenols, certain hydrocarbons such asbenzol, naphthenic acids, nitrogen base compounds and the like from oils such as tar oils, petroleum oils; shale oils and the like by treating such oilswith a strongaqueous solution of an organic material capable of dissolving suchingredientswhen the solution is in concentrated form, diluting such solution to separate out such ingredients in substantially unchanged condition, and-recovering such'ingredients. i

A i'urther'object' of this invention is to 'pro-' vide a. process of' extracting certain ingredients which are but slightly'solublein water from oils by treating such oils witha strong aqueous so-.

lution of an organic salt capable of dissolving such ingredients when the solution is i'n concentrated form and recovering the ingredients from suchsolution. i 1 A further object of this invention is to provide a process of extracting tar acids or phenols from tar oils by treating such oils with a strong aque-* ous solution of sodium'cymene"sulfonate.

Other objects and advantages of this invention will be apparent during the course of-the following descrip'tion. g

5 While the process forming the subject matter of this invention-is applicable to the extracting of ingredientsof the character referred to'herein it is particularly adapted for use in connection with the extraction of .tar acids from -tar oils and this particular application of the process is described as the preferred embodiment "of the invention. It'is to be understood, however, that the inventionis not limited to such application of the process. I

Heretofore tar acids. have been removed or extracted from the 'tar oil which is obtained by redistilling tars which are obtained in the distillation of coal, by treating the taroil with a. solution of caustic soda; usually of approximatelylo per cent. strength. Such solution-is then separated from the remaining insoluble portionoi the oil and is then treated with a sufiicient'a-mount of an acid, .Iusually sulphuric or carbonic, to completely neutralize the caustic soda. The tar .aci'ds or phenols are thenseparated out and are drawn off and 'purifiedby distillation. In this procedure the .causticrsoda reacts with the phenols present in the'oil to form sodium phenolates which arexsoluble in water.

The solution of sodium phenolates is then treated with an acid'to iorm the sodium salt of the "acid and free phenols. This process is-expensive due to the complete loss of the caustic soda, and the I acid employed and the minor difficulties 'attendant upon the recovery of the phenols from the milky-solution obtained on precipitation withthe acid; Moreover this process involvesh'andling acids and strong caustic material whichris a distinct disadvantage. v 1 v 'I have discovered thatthe mixture of crude phenols obtained from low 'temperaturetar dis- 'tillation and the similar mixture of phenols obtained from high temperature distillation while substantially insoluble in waterare readily. soluble in a concentrated aqueous-solution of arm monium acetate; sodium benzene sulfonate; j

sodium' cymene sulfonate, sodium naphthenates orin various' other saltsolutions as well as in solutionsoforganic materials which are not salts of true acids, or-in aqueoussolutionsof some acids such as benzenesulfonic acid, or in mixtures of such solutions. The organic materials which are not salts or true acids andthe above mentioned acids; such as benzenesulfonic acid, are to be considered equivalents of the organicsalts of the characterreferred.-to.,I have also discovered that on simple dilution of these solutions of phenols the phenols will separate out leaving the dilute solution" substantially free -from,' such phenols; Furthermore on evaporation. of this aqueous solution any small amount of phenols remaining therein 'willdistilloff with the'steam and can be recovered in thedistillate; A'distinct advantage oi this procedure is that the resulting solution after being concentrated back to its original strength can be used again for dis-' solving additional phenolic tar acids.

In the preferred practiceof my process'T pre fer to employ a relatively strong solution 'of an preferably a one-half I saturated solution or stronger, and this solution may be either neutral,

alkaline, or acid without affecting the desired result except that if more stronglyalkalinethan content is dissolved in the aqueous solution leaving alkali sulfonate, such as sodium cymene sulfonate i ratorto approximately its original strengthjfor reuse inthe practice of the process and the water condensate from the evaporator is employed for the hydrocarbons and other insoluble products in the residual oil. The aqueous solution-carrying the tar, acid? is then diluted/with wat,er.,. the water being added preferably in an amount equal to about one-half of the volume of the 's'o'lutic'in;

the exact proportion of water to be added de-: pending on the original concentration of the solvent solution, on the solute-employedinithe;-

solvent solution, on the material being dissolved; and on the temperature of 0peration=- Thetar acid separates out and isdrawn on" or recovered in any suitable manner.- The aqueoussolution is then evaporated until it has reached-its original concentration when it may be again employed column is filled with the liquids and the process is a. continuous counter-current one, the aqueous extracting. solution carrying approximately, all of the phenols removed from the oil settling to the bottom and beingdrawn ,offdandthe oil substantially freefrom phenols being drawn offat the top.. The feature of introducing the extracting solutionv at the second or third plate fromthe top of the apparatus prevents the loss of such materialby entrainment in the tar oil which is drawn off at. the top. The feature of introducing thetar oil'at a point spaced from the bottom of the apparatuspermits the aqueous solution. to separate completely from the tar oil whereby it is substantially free fromdrops of oil mechanically held therein.

z. The aqueous solvent solution carrying the phenols after. having been drawn offirom the apparatus" is diluted withwater in the manner described. Thephenols which are-substantially insoluble in this dilute solution separate out as ,a liquid layer whichisdrawn off. The remaining dilute'solution is then concentrated in an evapofurther diluting the succeeding solutions ,of phenols whereby every trace of the phenols which did not separate on dilutionis recovered,-

U .The; process is preferably Jcarried out atii as near atmospheric pressureas possible, no decided advantage being obtained in-operating the process ata pressure in excess of that required to; pro? vide for'thedesired flow of liquids. Moreover the process can. advantageously becarried out at ordinary ftemperatures if a solute which gives suflicient solvent character to the. water. is selected. When employingsolutes which give less solvent character to the waterit is advantageous to employ somewhat elevated temperatures, for example around 50 (1., since the solubility of the solute in water generallyincreases with the temperature and thereby the solvent character'of the water for the tar acids-is increased. As indicated by tests conductedthe tar acids are not much more soluble in the hot solution than inacold solution, provided that the concentration'ofthe extracting solution remainsthe same in both cases. The process can be handled essentially as a closed counter-current system with no substantial expense of operation. except the minor expenses attendant upon the evaporation required. A particularadvantage of thisprocess is that it avoids the expense due to the loss of chemicals andto the use of; strongacids and alkalish 'f 1 1.. Q;

In addition to extracting phenols I have discovered that if a strong solution of the solute materials, such as sodium cymene sulfonate, is employed, aromatic hydrocarbons such as benzol may to a certain extent-'*be-extracted by my process. The solubility of such hydrocarbons in the extractingsolution is pronounced but is not as great as in the case of phenolic compounds. The process is :also applicable to the extraction or purification-of reduced phenols such as hexhydro- ,phenol;;also to dissolving such materials as naphthenic acids and can be applied to the removal .of such" acids; from. naturally occurring petroleum oils. containing. they-same. .Moreover the. process may be applied. to. the removalgof nitrogen bases fromshale oils carrying .substantial amounts of such bases.

7 "By proper choiceof concentrationsof thesolute in the solvent solution it ispracticableto extract fractionally or in series from an oil'first-a-more soluble and then a less soluble constituent; e. g; tar, acidsandthen aromatic hydrocarbons from a tar oil. Also-the reverse-processimaybe can ried out,,e. g. tanacids and aromatichydrocar. bons ,mayfirst be extractedfrom ataroilby means of a relatively, concentrated solution of sodium cymene sulfonate, then .by proper dilution the dissolved aromatic hydrocarbons caused to separate out and be removed and then-byzfurther dilution the tar. acids separated out and;removed,; after which the diluted, aqueous solution may be evaporated to theoriginal concentration and reusedin the furtherpractice of the process. It will be apparent that if it is so desired thegoil may be; treated with aplurality of solutions ofa solute of the, character referredto; of progressively increasing strength and each of the resulting solutions diluted with water so'that the sub-, stantially water insoluble ingredients in the several fractions may be separately-recovered. By the term salt ofa base-formingmetalfias employed in the claims is meant a salt of: an alkali metal of the; character referred. to herein and' the term includes the hypothetical. basef orming metal ammonium. V V I -While Ihave described in detail; the preferred practice of my process it is tQ'bB understood that the details of procedure outlined may be widely varied without departing from the spirit of vthe invention or the scope of the subjoinedclaims. Iclaim: Q y 1. The process'of extracting and recovering substantially water insoluble ingredients of ring structure from oils containing the same which comprises treating such oils with a;relative1y strong aqueous solution of an organic acid salt of a base-forming metal to extract such ingredients therefrom,- separating such solution together withthe; extracted ingredients dissolved therein, diluting .such solution, and recoveringsaid ingredients. v 2. An extraction process of the character described comprising itreatin'g hydrocarbon oils containing substantially water insoluble ingre dif ents to be extracted; with a relatively strong aqueous solution of anorganic acid salt of a base i forming metal to dissolvesuchingredients, separating such solution together with the extracted ingredients dissolved therein from; i the (Jill being scribed comprising treating oil containing substantially water insoluble ingredients I of ring structure to be extracted, with a relatively strong aqueous solution of an organic sulfonate of a base forming metal, separating such solution together with the extracted ingredients dissolved therein from the oil being treated, diluting such solution, and recovering such ingredients.

4. An extraction process of the character described comprising treating oil containing substantially water insoluble ingredients of ring structure to be extracted, with a relatively strong aqueous solution of sodium cymene sulfonate, separating such solution together with the extracted ingredients dissolved therein from the oil being treated, diluting such solution, and recovering said ingredients.

5. The process of extracting and recovering phenols from oils which comprises treating such oils with a relatively strong aqueous solution of an organic salt of a base-forming metal having a pH of less than 13, separating such solution together. with the phenols dissolved from the oil being treated, diluting such solution,- and re covering the phenols.

6. The process of extracting and recovering tar acids from tar oils which comprises treating such oils with a relatively strong aqueous solution of an organic sulfonate of a base-forming metal, separating such solution together withv the tar acids dissolved from the oil being treated, diluting such solution, and recovering the tar acids.

'7. The process of extracting and recovering tar acids from tar oils which comprises treating such oils counter-currentwise with a relativelystrong aqueous solution of an organic salt of a base-forming metal, separating such solution together with the tar acids dissolved from the oil.

a relatively strong aqueous solution of an or-.

ganic salt of a base-forming metal to dissolve said ingredients.

9. In a process of the character described for extracting certain substantially water insoluble ingredients from hydrocarbon oils containing the same, the step of treating such oils with a relatively strong aqueous solution of an organic 'sulfonate of a base-forming metal to dissolve said ingredients.

10. In a process of the character described for extracting certain substantially waterin'soluble ingredients of ring structure from oils containingthe same, the step of treating such oils with a relatively strong aqueous solution of sodium cymene sulfonate to dissolve said ingredients.

11. A process of the character described for extracting and recovering certain substantiallywater insoluble ingredients from hydrocarbon oils containing the same which comprises treating such oils with a relatively strong aqueous solution of an organic acid salt of a base-forming.

the step of recovering substantially water insoluthe resulting solutions with water, and recovermetal to dissolve said ingredients, separating such solution together with the extracted ingredients dissolved therein from the oil being treated, and successively diluting and recovering said ingreclients. i

12. The process of extracting and recovering certain substantially water insolubleingredients of ring structure from oils containing the same which comprises treating such oils with a relatively strong aqueous solution of an organic acid salt ofa base-forming metal to dissolve said ingredients, separating such solution together with the extracted ingredients dissolved therein from the oil being treated, and fractionally diluting such solution with waterand recovering said ingredients.

13. In the herein described extraction process,

'the step of recovering substantially water insoluble ingredients of ring structure dissolved in a relatively strong aqueous solution of an organic acid salt of a base-forming metal-which comprises treating such a solution with water.

1 1. In the herein described extraction process,

ble ingredients of ring structure dissolved in a relatively strong aqueous solution of an organic sulfonate of a base-forming metal which comprises treating such a solution with water.

15. The process of extracting and recovering certain substantially water insoluble ingredients comprises treating such oils counter-currentwise with a relatively strong aqueous solution of an organic acid salt of a base-forming metal, sepa- I rating such solution together with the extracted ingredients dissolved therein from the oil being treated, diluting such solution, and recovering said ingredients. i

16. An extraction process of the character described comprising treating a current of 011115 containing substantially water insoluble ingredients of ring structure to be extracted, with a counter-current of a relatively strong aqueous solution of an organic acid salt of a base-forming metal to extract said ingredients from said oil, separating such solution together with the extracted ingredients dissolved therein fromsaid oil, diluting such solution, recovering said ingredients, concentrating the diluted solution, and reusing the same'in the counter-current treatment.

17. The process of fractionally extracting certainsubstantially water insoluble ingredients of ring structure from oils containing the same which comprises, treating such oils with a plurality of solutions of progressively increasing strength of an organic salt of'a base-forming metal, diluting ingsaid ingredients.

13. The herein described process of dissolving phenols, aromatic hydrocarbons, naphthenic acids and nitrogen bases such as are foundin, petroleum oils in an aqueous solvent which comprises mixing the material to be treated with a relatively strong aqueous solution of an organic salt of abase-forming metal. 4

. RALPH H. MCKEE.

105 y from hydrocarbon oils containing the same which 

